Fascinating Phenomena in Gemstones

There are several varieties of gemstones that display optical phenomena, which describes the many ways light interacts with the structural features or inclusions (internal characteristics) in the gemstone. Often these gemstones will be fashioned in a particular way that best displays these effects.

The science of optical phenomena can be fascinating, although the mystery and allure of these effects are what initially attract us! Below are six of the most familiar (and magical) displays of optical phenomena in gemstones.

Play-of-Color

Play-of-color is created by a combination of diffraction and interference, and is the result of the microstructure of opal: the chameleon of a thousand colors and October’s birthstone!

Opals are made up of many layers of small, stacked spheres of silica. These spheres diffract light, splitting it into a spectrum of colors. The layers of these spheres create interference allowing certain colors to dominate, depending on the angle the opal is viewed.

Asterism

Asterism, or stars, relates to the four- or six-rayed star pattern of light produced by the fibrous inclusions, elongated needles, or growth tubes in a gemstone. This singular, celestial-like phenomenon is best seen in a gemstone cut en cabochon.

 

Chatoyancy

Chatoyancy [sha-TOY-an-cee] is also known as “cat’s eye.” Fine needle-like or fibrous inclusions within the gemstone are what causes this effect. Again, stones fashioned as cabochons display this effect the best.

 

Color Change

A small number of gemstones display the color change optical phenomena. Depending on the lighting environment, the color change appearance can vary due to the shifting wavelengths. The technical term for this is photochromism or photochroism; “color-change” is a lot easier to say!

The best-known color changing gemstone is alexandrite. When viewed in sunlight, it appears greenish. When placed under incandescent light, it appears reddish. Other varieties of color-changing gemstones include sapphire, garnet, spinel, diaspore, and tourmaline.

 

Adularescence

Adularescence is the phenomenon typically seen in moonstone, which is a member of the feldspar family. It produces a billowy soft blue to milky white light that appears to move across the gemstone. This occurs when light hits the alternating layers of albite and orthoclase, which are two differing forms of feldspar within the gem.

The layers of feldspar interfere with the light rays causing them to scatter and the eye to observe adularescence. The effect is best seen when the gemstone is cut en cabochon [en CAB-ah-shawn]—that is, with a polished, domed top and a flat or slightly rounded base.

 

Labradorescence

Labradorscence [lab-ra-dor-es-cence] is an optical characteristic often seen in labradorite. The effect is a spectacular play-of-color that is metallic or iridescent, displaying blue, green, red, orange, and yellow. This is an interference effect within the gemstone caused by internal structures that selectively reflect only certain colors.

 

Are you ready to see some of these displays in person? Visit an American Gem Society (AGS) jeweler near you and ask to see some gemstones that exhibit optical phenomena!

Color Comes Into Play with October’s Birthstones

Opal-Tourmaline2

Opal and tourmaline from Gem 2000.

When it comes to color choices, October’s birthstones give you some amazing choices. Whether you choose opal or tourmaline, you’ll get a display of exciting and intense colors, making them popular choices for jewelry designers and collectors.

Opal

The name “opal” derives from the Greek opallos, meaning “to see a change (of color).” They range in color from milky white to black with flashes of yellow, orange, green, red, and blue. An opal’s beauty is the product of contrast between its color play and its background.

Opal is a formation of non-crystalline silica gel that seeped into crevices in the sedimentary strata. Through time and nature’s heating and molding processes, the gel hardened into the form of opals. The opal is composed of particles closely packed in spherical arrangements. When packed together in a regular pattern, a three-dimensional array of spaces is created that gives opal its radiance.

Approximately 90 percent of the world’s precious opal comes from Australia. The following are other countries that produce precious or fancy varieties: Brazil, Mexico, United States, Hungary, Peru, Indonesia, Honduras, Guatemala, Nicaragua, Slovakia, Czech Republic, and Ethiopia.

Each opal is totally unique, like fingerprints!! To get a really good look at the opals in these designs, click on the images below for a larger view.

Tourmaline

Since tourmaline is available in a wide variety of colors, it is ideally suited to almost anyone’s taste. It is known for displaying several colors in the same gemstone. These bi-color or tri-color gems are formed in many combinations; the gemstones with clear color distinctions are highly prized.

Tourmaline is found in many localities including Brazil, Afghanistan, East Africa, and the USA.

The following designs feature the varying hues of tourmaline. Click on the images to see a larger view.

 

If you are shopping for opal or tourmaline jewelry, click here to search for an American Gem Society (AGS) credentialed jeweler near you.

 

Corundum of Many Colors: Sapphire

As we turn our calendars to September, we start thinking of things like heading back to school, sipping on a pumpkin spice latte, and planning our fall fashions. For those celebrating a birthday in September, they’re thinking of their birthstone: sapphire!

Although sapphire typically refers to the rich blue gemstone variety of the mineral corundum, this royal gem actually occurs in a rainbow of hues. Sapphires come in every color except red, which would then be classified as ruby.

Trace elements like iron, titanium, chromium, copper, and magnesium give naturally colorless corundum a tint of blue, yellow, purple, orange or green, respectively. Sapphires in any color but blue are called “fancies.”

Pink sapphires, in particular, tow a fine line between ruby and sapphire. In the U.S., these gems must meet a minimum color saturation to be considered rubies. Pinkish orange sapphires called padparadscha (from the Sri Lankan word for “lotus flower”) can actually draw higher prices than some blue sapphires.

Due to the remarkable hardness of sapphires—which measure 9 on the Mohs scale, second only to diamond—they aren’t just valuable in jewelry, but also in industrial applications including scientific instruments, high-durability windows, watches, and electronics.

Sapphires make stunning gifts for anyone born in September or celebrating a 5th or 45th wedding anniversary, so be sure to visit an AGS jeweler. They will help you find that perfect gift, whether you’re seeking the classic blue or another shade from the sapphire rainbow.

Need some inspiration? View this collection of designs featuring the sapphire!

Jewelry Trend Watch: East-West Settings

If you’re looking for a style that takes traditional in a different direction, check out the east-west setting. It’s the lastest jewelry trend that places the gemstone horizontally vs. the classic vertical setting. Whether the cut is oval, pear, marquise, or emerald, the east-west setting will be noticed!

We’re spotlighting a few designs from our AGS members that feature this eye-catching setting. Click on the images to get a closer look.

 

 

Looking to see some east-west set jewelry in person, visit an American Gem Society credentialed jeweler near you: www.ags.org/findajeweler.

Four Fine Jewelry Trends for Spring 2019

Spring is here and we’re ready for some jewelry trends to help us celebrate this much-welcome change of season! Now that the weather is warming up, what’s hot? We’ve gathered some season-sensational (We just made that up!) designs from our AGS members.

Quite possibly the most quintessential symbols of spring are flowers, butterflies, and bees. Naturally, their likenesses are found in a variety of fine jewelry designs.

 

Next on the list is chains. Big chains. Little chains. This trend is an ode to the Eighties and they’re everywhere!

 

It’s been said that pearls never go out of style, but these aren’t your grandmother’s pearls! Modern designs have re-imagined the classic jewelry wardrobe staple.

 

The warmer weather has us looking towards the sky and the sea for a much-needed getaway! Both celestial and nautical-themed designs inspire us to seek the outdoors (and beyond) for our next adventure.

 

Are you ready to add a bit of bling to your spring wardrobe? Find an American Gem Society jeweler member near you at www.ags.org/findajeweler.

3 Gemstones That Sparkle for the 4th of July

By Robin Skibicki

Dilamani

Ruby, diamond, and sapphire brooch by Dilamani.

The American Independence Day—or the Fourth of July—is when we celebrate our country’s freedom and the adoption of the Declaration of Independence. It’s also considered the height of summer!

It’s a time for family reunions, barbeques, picnics, parades, and the much-anticipated fireworks displays. On this day, we proudly display our nation’s colors: red, white, and blue.

Fun Fact: More than 14,000 firework displays are put on across the country on the Fourth of July!

But don’t let those fireworks grab all the attention. Create your own sparkle-fest with three gemstones that will beautify your patriotic style. We’re talking about rubies, white diamonds, and blue sapphires!

In honor of the holiday, we’ve picked a few designs by our American Gem Society members that feature one of the three, aforementioned gemstones. Click on each image below to get a closer look.

Red Rubies

 

White Diamonds

 

Blue Sapphires

 

May your Fourth of July celebration be sensational, safe, and full of sparkle! To find an AGS-credentialed jeweler near you, visit http://www.ags.org/findajeweler.

5 Pieces of Jewelry to Take on Your Summer Vacation

By Robin Skibicki

“Summer, summer, summertime / Time to sit back and unwind.” – DJ Jazzy Jeff & The Fresh Prince, Summertime

As thoughts of summer vacation drift through our heads, so does the ultimate question: “What am I going to pack?!” Whether you’re traveling overseas, across states—or even planning a staycation—it’s good to have a plan.

Although we’d love to help you pick out your various outfits and toiletries—they aren’t our area of expertise. But we CAN give you some great ideas on what jewelry to bring with you.

It’s often a challenge deciding which items of jewelry to take, depending on the outfits you pick. But it’s important to note that it’s best to leave the most valuable and delicate pieces at home. Before you pack, we have this recommended read from Jewelers Mutual Insurance Group: The Pocket Guide to Traveling with Jewelry.

Yet, no outfit is complete without the punctuation of fine jewelry. Here are five pieces from a few of our AGS members that would make great travel companions! Click on the images below to get a closer look.

“Caprice” multiway diamond eclipse earrings, by Mastoloni.
When you can bring one pair of earrings and wear them three different ways, you’re covered! Wear as a dangle, as a diamond and pearl stud, or wear the pearl by itself.

 

Wide diamond band from Gabriel & Co. “Lusso” collection.
A diamond band with alternating 14k yellow and white gold gives the illusion of wearing multiple rings. Easy peasy!


Gabriel-14k-Yellow-And-White-Gold-Lusso-Wide-Band-Ladies-Ring_LR50892M45JJ-3

 

Two-piece convertible diamond heart pendant, by Lisa Bridge, Ben Bridge Jeweler.
This romantic pendant is convertible and can be worn three ways: with both diamond pavé and heart pieces together, or either the center circle or heart frame separately.

 

Rainbow sapphire butterfly brooch, by Dilamani.
A brooch you say? You bet! Dress up any top, scarf, hat—or even a hairstyle—with a brooch. A brooch can also be turned into a pendant with the addition of a chain. So many style options!

 

Custom reversible classic chain bracelet, by John Hardy.
Here’s another “gem” we found: one bracelet with two looks! John Hardy gives you the opportunity to customize your own chain bracelet with any gemstone look. Below is the combo we designed. The 18k bonded gold side sparkles with diamond pavé. The sterling silver side has a pop of color with amethyst. Which look would you create for yourself?

 

Visit an American Gem Society jeweler near you for more helpful hints on what to bring—and what not to bring—on your summer vacation. Happy travels!